DamID, in which a protein of interest is fused to Dam methylase, enables mapping of protein-DNA binding through readout of adenine methylation in genomic DNA. DamID offers a compelling alternative to chromatin immunoprecipitation sequencing (ChIP-Seq), particularly in cases where cell number or antibody availability is limiting. This comes at a cost, however, of high non-specific signal and a lowered spatial resolution of several kb, limiting its application to transcription factor-DNA binding. Here we show that mutations in Dam, when fused to the transcription factor Tcf7l2, greatly reduce non-specific methylation. Combined with a simplified DamID sequencing protocol, we find that these Dam mutants allow for accurate detection of transcription factor binding at a sensitivity and spatial resolution closely matching that seen in ChIP-seq.

中文翻译：

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Dam突变体可提高谱图转录因子结合的灵敏度和空间分辨率。

DamID将感兴趣的蛋白质与Dam甲基化酶融合在一起，通过读出基因组DNA中的腺嘌呤甲基化，可以绘制蛋白质-DNA结合图。DamID为染色质免疫沉淀测序（ChIP-Seq）提供了一种引人注目的替代方法，尤其是在细胞数量或抗体可用性受到限制的情况下。然而，这是以高的非特异性信号和降低的几个kb的空间分辨率为代价的，这限制了其在转录因子-DNA结合中的应用。在这里，我们显示当与转录因子Tcf7l2融合时，Dam中的突变会大大减少非特异性甲基化。结合简化的DamID测序方案，我们发现这些Dam突变体可以精确检测转录因子结合，其灵敏度和空间分辨率与ChIP-seq十分接近。